Metropolitan Washington's 22,000 federal wage board workers -- carpenters, mechanics and other craft employes -- have been given pay raises of nearly 4 percent retroactive to Oct. 17.

The government also approved similar retroactive raises yesterday for 2,200 civil servants here who are paid under the so-called printing and lithographic scale.

Although government pay surveys showed that pay for similar jobs in the private sector here is up nearly 6 percent, the federal blue-collar (wage grade) workers are subject to the same 4 percent pay raise ceiling that was applied last month to raises for nearly 300,000 white-collar federal civilians here.

Raises for nonsupervisory blue-collar personnel will range from 21 cents an hour to 50 cents an hour.

Major employers of blue-collar workers are, in order, Navy, Army, Health and Human Services, General Services Administration and the Air Force. There are also substantial numbers of blue-collar workers in other Defense units, Agriculture, Interior, Commerce, the Smithsonian Institution and Transportation.

The raises cover employes in the standard metropolitan area, plus the Maryland counties of Calvert, Frederick and St. Mary's, and in Virginia the counties of Fauquier, King George and Stafford.

Unlike white-collar federal employes who get the same percentage pay raise each October no matter where they work, blue-collar workers are supposed to get raises linked to industry pay rates in more than 140 geographic areas.

Pay rates for blue-collar feds here are set by the Defense Department and come due in mid-October. The most recent local wage survey run by the government showed that non-federal blue-collar salaries have risen 6 percent since last year. Normally feds would get the same amount. But Congress has put a 4 percent limit on blue-collar pay to match the 4 percent cap President Reagan imposed on white-collar civil servants.

With the new increase, the average salary for nonsupervisory blue-collar workers will rise to $17,825, according to the Defense Department. The typical white-collar (GS) government worker here earns more than $26,000 a year, according to the Office of Personnel Management.